Project Sedan, Nevada Test Site, July 6, 1962. Sedan Long Range ...
Transcript of Project Sedan, Nevada Test Site, July 6, 1962. Sedan Long Range ...
PN E-202FFINAL REPORT
1c / peaceful uses for nuclear explosives
UNITED STATES ATOMIC ENERGY COMMISSION I PLOWSHARE PROGRAM
projectNEVADA TEST SITE / JULY 6, 1962
//
0 00
Las Vegas
Sedan Long Range Blast PropagationJack W. Reed / Hugh W. Church
SANDIA CORPORATION ISSUED: AUGUST 30, 1963
DISTRIBUTION STATEMENTAApproved for Public Release 20050824068
Distribution Unlimited
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PNE-202F
Project Plowshare
SEDAN LONG RANGE BLAST PROPAGATION
Final Report
Jack W. Reed
Hugh W. Church
Sandia Corporation, Albuquerque, New Mexico
June 1963
ABSTRACT
Microbarograph records of air-blast waves from the Sedan shot were made at
eight stations in California and Nevada at ranges from 100 to 230 miles. A 1.2-
ton high-explosive calibration shot was fired at Sedan ml=92 minutes to estab-
lish propagation conditions for bursts in air. Comparison of recorded signals
indicated that Sedan blast-wave amplitudes averaged 20 percent of amplitudes
which would have been transmitted had the Sedan yield been free-air burst. In-
dividual transmissivity values ranged from 5 to 35 percent. Variations around
the average are probably caused by atmospheric turbulence.
Sedan blast waves were ducted toward the west by atmospheric refraction
in the ozonosphere where strong summer easterlies were blowing at 100.,000- to
200,000-foot altitudes. Rocket wind measurements were made at Tonopah Test Range.
Rocket and rawinsonde data were used to calculate atmospheric blast propagations
which are in fair agreement with microbarograph measurements.
2
TABLE OF CONTENTS
Page
INTRODUCTION ........................... .............................. 5
EXPERIMENT PLAN .......................... ........................... 5
INSTRUMENTATION .......................... ............................ 6
RESULTS .......................... ................................ .. 12
CONCLUSIONS AND RECOMMENDATIONS .............. .................... .. 29
REFERENCES ....................... ............................... ... 31
ILLUSTRAT IONS
1. Sedan microbarograph stations ........... .................. . . 72. Raypac (Atmospheric Sound Ray Computer) and plotter at
CP-I, NTS ........................... ............................ 93. Sedan microbarograph recordings ............... .............. .• 14
4. Microbarograph recordings of HE calibration shot fired at
Sedan minus 2 minutes ............... .......... ..... ...... 15
5. Maximum pressure-wave amplitudes ............ ................ .. 16
6. Platform used in firing HE calibration shots; height, 15 feet . . . 18
7. Air-blast transmission factors from high-explosive and nuclear
cratering tests ................... .......................... .. 21
8. Pressure-amplitude-versus-distance predictions and observations
at various direction bearings, normalized to calibration shot
yield ......................... .............................. .. 23
9. Calculated pressure-distance curves from two assumed atmospheric
models ........................ .............................. .. 24
10. Calculated mean speeds to wave arrival for two assumed atmos-
pheric models ..................... .......................... .. 26
11. Verification scatter diagram for HE calibration shot .. ....... o.27
12. Pressure-distance data extrapolated to 50-mt cratering shot . ... 28
3
TABLES
Page
1. Bearings and Ranges from Shot Points to Microbarograph Stations . 8
2. Upper Air Observations Used for Sound-Ray Calculations .. ...... .. 11
3. Sedan Microbarograph Data Summary ......... ................. ... 13
4. Sedan Transmission Factors .............. .................... .. 20
Project Plowshare
SEDAN LONG-RANGE BLAST PROPAGATION
INTRODUCTION
The Sedan shot was a 100-kiloton nuclear device burst 635 feet below the
surface in Yucca Flat, Area 10, of the Nevada Test Site (NTS). Shot time was
1000 PDT, July 6, 1962. The test was conducted to give cratering effects data
on nuclear excavation in desert alluvium. Results are to be applied to the
design and safety evaluation of future Plowshare nuclear excavations.
Microbarograph measurements were made at ranges to 230 miles to provide
data for scaling and the assurance of off-site safety of future larger cratering
experiments. Similar measurements on Plowshare high-explosive (HE) testsl' 2 ' 3
have shown approximately how air-blast transmissions were decreased with in-
creased scaled depth of burst. This transmissivity appeared to be larger for
shots in basalt(Buckboard) 2 than for shots in alluvium (Stagecoach).' Trans-
missivity appear to increase with increased yield in Stagecoach-versus-Scooter 3
comparisons. It was believed that there would also be a difference between
nuclear and high-explosive transmissivities, but comparison between Teapot ESS4
and the Stagecoach shallow shot did not show any clear difference. There were
no other nuclear tests at depths near the optimum for cratering in similar
environments.
During the 1958-61 test moratorium, rocket upper wind measurements were
made operationally feasible so that ozonosphere weather conditions could be ob-
served. These observations could be used to calculate ozonosphere sould refrac-
tion and blast ducting as was done in previous years for tropospheric ducting
for the purpose of making predictions for off-site safety. Sedan, Dannyboy, 5
and Smallboy shots provided the only opportunities thus far encountered at NTS
to test these high-altitude blast pattern calculations.
EXPERIMENT PLAN
In summer, ozonosphere winds at OO.,OOO- to 200,000-foot altitudes blow
from east to west and, from Nevada. refract blast waves into California, with
5
a caustic ring of relatively strong waves landing at between 100 and 150 miles
from surface zero. Waves in this ring reflect from ground, repeat the high
atmosphere path, and land again at 200 to 300 miles, etc. To study this pat-
tern, microbarograph stations were operated at eight sites in the southwest-
northwest quadrant from NTS as shown in Fig. 1. Shot and microbarograph loca-
tion coordinates and connecting bearings and ranges are listed in Table 1.
It was planned to fire 1.2-ton high-explosive calibration shots at H minus
2 minutes and H plus 3 minutes to record the general propagation of known-yield
air blasts. Comparison of signals from these shots with the intervening Sedan
signal would allow calculation of the air-blast attenuation factor or its in-
verse, the transmissivity, from the buried nuclear device.
Near shot time, a rocket wind measurement of ozonosphere winds and a
balloon-borne rawinsonde measurement of troposphere winds and temperatures were
to be made. Weather data from these soundings were to be used to compute
directed sound velocities at various altitudes. From the sound velocity struc-
ture a computation of refracted sound-ray paths could be made on the Raypac
computer at the NTS control point (CP-l). This analogue sound-ray computer
is shown in Fig. 2. Sound-ray paths indicate where a blast wave would return
to ground, and the ray spacing, when combined with blast yield, allows a cal-
culated pressure-amplitude prediction. Calculated predictions were to be
compared with signals from both the HE calibration shots and the Sedan signal
to give statistical information on prediction errors. Also, the three event
records (two HE and one nuclear) of the blast signals at each station could be
compared to show short-term variability of atmospheric propagations caused by
turbulence.
Finally, results were to be scaled up to larger yields to demonstrate
the magnitude and relative importance of blast safety predictions.
INSTRUMENTATION
Microbarographs used for this project were similar to those used for years
in recording nuclear tests. Differential pressure-wave sensors were twisted
Bourdon tubes which turned an armature with respect to an E-core. Varying
reluctance in the E-core is used to modulate a carrier wave transmitted by
6
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Table 1. Bearings and Ranges from Shot Pointsto Microbarograph Stations
Station Sedan HE calibration
370 10' 37.225" North 370 10' l 43.668" North
1160 02' 43.359" West 1160 01' 13.791" WestElevation 4323 ft MSL Elevation 4423 ft MSL
CP-I 360 56' 04.896" N 181.550 186.180El. 4120' 1160 03' 12.800" W 88,44o' 89,580'
Argus 350 42' 55.417" N 217.150 217.630El. 1750' 1170 24' 07.303" W 665,473' 670,383'
China 350 41' 34.363" N 222.050 222.450Lake
El. 2200' 1170 40' 51.998" W 723,652' 728,999'
Valley 350 12' 19.185" N 234.960 235.140Acres
El. 6OO' 1190 24' 10.327" W 1,222,440' 1,228,740'
Lone 360 35' 24-023" N 250.54' 250.720Pine
El. 3700' 1180 03' 17.139" W 624,248' 631,288'
Deep 370 22' 21.535" N 277.770 277.620Springs
El. 5300' 1170 59' 52.753" W 571,360' 578,440'
Bishop 370 21' 26.221" N 276.210 276.110El. 4190' 1180 23' 47.147" W 685,778' 692,899'
Tom's 370 33' 38.438" N 281.190 281.050Place
El. 7050' 1180 40' 43.713" W 776.331' 783,303'
Coaldale 380 01' 35.940" N 300.840 300.460El. 4630' 1170 52' 54.087" W 614,679' 620,568'
8
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coaxial line into appropriate signal amplifiers for recording. Sensor heads were
manufactured by Wiancko Corporation, Pasadena, California, as specified and eval-
uated by Sandia Corporation. 6 Amplifier and timer systems in current use were
designed at Sandia and built by the Electronic Engineering Company, Santa Ana,
California. Brush Electronics Company pen-type recorders were used at a paper
speed of 2.5 centimeters per second, with 1-second time marks by an event--marking
pen. Zero-time signals'for both calibration and Sedan shots were transmitted on
NTS Net 12 radio and recorded on each pressure trace. Combined instrument and
recorder response time for pressure signals was such'that 95 percent of pen de-
flection from a square-wave pressure pulse would be recorded in about 15 milli-
seconds. Thus, there is very little amplitude damping for signals having fre-
quencies lower than 10 cps.
Sandia microbarographs have seven set-range switch positions, which allow
signal amplitudes from 1 microbar to 48 millibars* to be satisfactorily recorded,
provided ambient wind noise at low signal levels and blast damage at high pres-
sure levels are not excessive. Recent calibration tests have disclosed that
nearly 85 percent of all recordings were accurate to ±20 percent.
Wind rockets were launched from Tonopah Test Range (see Fig. 1) after the
Sedan shot was fired. A Judi rocket motor, manufactured by Rocket Power, Inc.,
Phoenix, Arizona, carried a Dart payload nose to 255,000 feet msl. This 30-
pound system carried a 1.5-pound payload of copper-wire chaff, each piece 5 cm
long and 5 x 10-3 inch in diameter. Chaff of this size falls freely to about
200,000 feet where air density and drag become sufficient to carry it with the
wind as it falls down to around 50,000 feet. Timed chaff-cloud tracks reported
by a modified MPS-25 radar furnished wind observations through height layers.
Sandia rocket wind measurements have been analyzed and reported by Smith. 7
These winds were used with sound speeds derived from ARDC 1962 Standard Atmos-
phere temperature data8 from 90,000 feet to approximately 188,000 feet, as
shown in Table 2. Rawinsonde balloon observations of the troposphere and low
stratosphere were made by the U.S. Weather Bureau in Yucca Flat from ground
level to 86,000 feet msl.
1 millibar = l03 dynes/cm2 = 0.0145 psi m 10-3 atmospheres (STP).
10
Table 2. Upper Air Observations used forSound Ray Calculations
Height Temperature Wind direction Speed(kilofeet, msl) (°c) (degrees) (knots)
4 +31.0 180 10
5 +26.5 150 13
6 +23.5 155 12
7 +20.5 177 10
9 +14.6 230 14
11 +8.8 197 28
14 +3.5 180 21
17 -o.6 188 6
23 -15.0 250 1
28 -25.7 296 6
33 -37.6 237 22
42 -54.5 250 3550 -65.2 225 25
54 -67.8 229 12
60 -62.5 180 16
65 -56.0 115 14
80 -49.8 100 28
86 -45.3 070 18105 -44.8 090 32
120 -32.5 095 45
140 -16.0 093 60
155 -2.5 100 102
170 -2.5 102 8418o -7.0 110 8o188 -12.0 095 127
11
RESULTS
Sedan was fired, as previously mentioned, at 1000 PDT, July 6, 1962. One
HE calibration shot was fired at 0958 PDT on schedule. The Sedan shot, however,
severed the firing cables to the site for a later scheduled HE firing, and the
latter calibration shot could not be detonated. Rocket wind measurements were
made at Tonopah Test Range at 1005 PDT and at 1630 PDT. Most microbarographs
appeared to have operated satisfactorily, and recordings were made of both shots.
Postshot calibrations from the Bishop station, however, showed that instrument
response was nonlinear and probably incorrect at low pressure amplitudes. Data
from this station are therefore suspect, particularly the HE signal pressure,
although the Sedan recording seems to be in line with surrounding data points.
In addition, at the Coaldale station there was considerable electrical noise
(6 cps) on the recording which undoubtedly produced HE pressure signal deflec-
tions greater than were anticipated. This did not adversely affect the lower
frequency, higher amplitude Sedan recording.
Sedan pressure amplitudes were somewhat larger than expected and caused
a slightly off-scale recording at China Lake. The Lone Pine operator erron-
eously used too sensitive a set range, and the recording was likewise driven
off-scale by the Sedan wave. The Tom's Place recording shows a long, flat pres-
sure maximum which may well have been the set-range limit.
A summary of major significant signal data is shown in Table 3, and the
most interesting portions of the various recordings are shown in Figs. 3 and 4.
Maximum amplitudes are shown on a pressure-distance plot in Fig. 5 for compari-
son with standard curve values. Observed pressures have been scaled to near
sea level values at 1000 millibars ambient pressure for comparison with standard
values. Ambient pressure at each station was taken from U.S. standard pressure
altitude tables8 for the surveyed station elevation. Actual barometric pressure
values would provide only sight correction beyond this adjustment.
The standard reference curves were derived from the IBM Problem M calcula-
tion9 for a 1-kiloton free-air-burst nuclear device at sea level (1000 mb). This
calculation was carried only to 9000 feet range, 0.37 psi (25.5 mb) overpressure.
At longer range, R, overpressure, Ap, follows Ap - R-1.2 in a homogeneous, non-
refracting atmosphere. In the IBM Problem M, negative-phase pressures approach
12
Table 3. Sedan Microbarograph Data Summary
Station Calibration shot Sedan
ta Pk V ta Pk V Remarks
CP-l 81.4 41.0 1100 8o.7 1394 1095 HE deflectionvery small.
Argus 673 46.8 - 997 ~ 664 376 1001 Timer troubles, t,V inaccurate.
China Lake 753 51.0 969 748 >828 967 Slightly off-scale.
Valley Acres 1177 6.2 1043 1172 106 1043
Lone Pine 671 41.0 942 656 >328 951 Possibly factor of2 off-scale onSedan.
Deep Springs 615 107 940 605 555 945
Bishop 714 13.8 970 708 685 969 Doubtful amplitudes.
Tom's Place 791 67.0 990 785 >750 990 Sedan signal mayhave limited.
Coaldale 654 130 951 645 320 954 Max. HE value maybe electric inter-ference.
NOTE: ta is arrival time in seconds;
Pk is peak-to-peak pressure amplitude in microbars;
V is average propagation speed in ft/sec.
13
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I0 -MB SET NO. STATION
5 ARGUS, CALIF.6 DEEP SPRINGS, CALIF. 10
- 8 COLDALE, NEV.9 TOMWS PLACE, CALIF.
10 VALLEY ACRES CALIF.II BISHOP, CALIO.14 CHINA LAKE, CALIFi15 LONE PINE, CALIF
10 4 108 I0 6 1io7
RANGE (FEET)
Fig. 5 Maximum pressure-wave amplitudes.
16
0.34 times the overpressure; from this, peak-to-peak pressure amplitude, Pk,
at large distance is assumed to conserve this relation so that Pk = 1"34 iLp"
The calibration shot was 1.2-ton uncased high-explosive (TNT) placed on
a wooden platform 15 feet above ground, similar to the one shown in Fig. 6.At this height of burst, the blast wave was equivalent to a wave from 2.1 tons
HE, free-air burst. The end point of IBM Problem M, 25.5 mb at 9000 feet range,
was scaled to give Pk = 1.34 x 25.5 = 34.2 mb at R = 9000 (4.2 t/l kt) 1 /3 =
1452 feet. Beyond this range, Pk = 53.5 (R kft)- 1 . 2 mb.
The apparent HE blast-yield enhancement caused by height-of-burst effects10
was derived from data published by Vortman and Shreve. Effects of height of
burst on blast pressures propagated to long range are according to Church. 1 1
Calibration HE shots were first fired on towers during the Buckboard project.
On Stagecoach they were fired at ground level. There remains some doubt that
the surface burst apparent yield value, 0.6W, used in Stagecoach, is correct.
If a larger value, i.e., 1.6W, as is generally used for nuclear surface bursts,
is more appropriate, Stagecoach transmission factors should be increased by
(1.6/0.6)0.4 = 1.48. This would result in negating previous conclusions that
(1) transmissivity from shots in basalt is larger than from shots in alluvium,
and (2) transmissivity increases with increased yield. Church's experiments with
HE spheres half-buried for zero height of burst, in addition to two pressure-
gage measurements at 300 feet from 1.2 tons of depth charges lying on the ground,
are not sufficient to adequately ease these doubts. Other more direct tests,
comparing 1.2-ton HE tower bursts with surface bursts, should be made.
Sedan, with a yield of 100 kilotons (nuclear), if free-air burst, would
have given a standard pressure-distance curve beginning at Pk = 34.2 mb at
R = 9000 (100 kt/l kt) 1 /3 = 41,800 feet, and would have followed Pk = 3010
(R kft)-1"2 to longer ranges. Figure 5 shows that some of the Sedan pressures
(off-scale records) probably exceeded standard values for air bursts. Since
the HE calibration records greatly exceeded the standard homogeneous atmosphere
propagations, Sedan results are not surprising. Atmospheric ducting and focus-
ing toward this downwind sector of observation stations on this particular day
caused considerable enchancement of pressure amplitudes from both shots.
17
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18
Records from CP-I, at too short a range to receive ozonosphere propagations,
show pressures much below standard characteristics of propagation upwind in an
unstable atmosphere, where sound velocity decreases with altitude to refract
blast waves away from ground level. Because of shot-point and azimuth-bearing
differences from the two shocs, HE propagation was more obscured from CP-I than
was propagation from Sedan, and in result was more reduced below the standard
curve.
Transmission factors for the Sedan underground burst were calculated by
extrapolation from HE calibration shot pressures to give predictions for a 100-
kiloton free-air burst. In this extrapolation, HE amplitudes were multiplied
by (100 kt/4.2 t)O'4 = 56.1, and the product was divided into observed Sedan pres-
sure amplitudes to give the transmission factor. The 0.4 yield exponent follows
directly from the scaled distance proportionality to the cube root of yield in a
region where overpressure decays as R-1 2 . Each recorded Sedan wave, which
clearly followed the same path (same mean travel velocity) as a comparable HE
wave, was used to calculate a transmission factor, as shown in Table 4. Values
that appeared to be least subject to significant error were averaged (logarith-
mically) to give a mean transmission factor of f = 0.199.
For the purpose of transmissivity comparisons, Sedan depth of burst at 635
feet is equivalent to a scaled depth of burst of 635/WI/ 3 = 137 feet for I kilo-
ton nuclear, or 1.37 feet for 1 pound HE, assuming nuclear explosives are 50% of
HE in blast production efficiency. Transmission data points for Sedan ozonosphere
signals, in addition to those for the Plowshare events, Stagecoach, Buckboard, and
Scooter HE tests, and for the Dannyboy nuclear event, are shown for their scaled
burst depths in Fig. 7. There is a large amount of scatter in each collection.
Agreement in the averages shows that the 0.199 figure from Sedan seems reasonable;
deviations by a factor of 1.5 or 2.0 are not uncommon in individual measurements.
Transmissivity at long range is approximately the same as was observed by
the on-site pressure gages reported by Vortman. 12 The off-site average value
is not significantly larger than the on-site values, as observed on Plowshare
HE cratering tests. Many individual Sedan transmissivity values are quite high;
however, they may represent emissions from the higher elevation angles from the
source. There were not adequate facilities or manpower available to make blast
pressure measurements above Sedan; therefore no check on the nonuniform source
19
Table 4. Sedan Transmission Factors
Station f Remarks
CP-l 0.5911. HE blocked by hill, f probablytoo large.
Argus m.146 Good records.
China Lake >0.269 Sedan slightly off-scale.
0.351* Good wave records.
Valley Acres 0.304* Good records early signal.
0.185 Possible later ozonosphereHE record is obscured inearly Sedan signal.
Lone Pine >0.152 Sedan off-scale.
Deep Springs 0.091* Good records.
Bishop 0.217* Amplitude scale doubtful, maynot affect relative amplitudeor f values.
Tom's Place 0.201* Good records.
>0.197 Sedan signal may be limitedby set range.
Coaldale 0.0506 (0.0675) Electrical noise may have added0.0456 (0.0532) to HE value, estimated f with
noise subtracted in parentheses.
*Subjectively judged to be most representative values.
Logarithmic average of starred * values = 0.199.
20
LARGER THAN INDICATED
SSMALLER THAN INDICATED
o DATA POINTS
o SEDAN POINTS USED IN AVERAGING
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21
wave model was possible. It would be of value if this effect, as described in
the Stagecoach analysis, could be verified by a measurement project on future
cratering tests.
Final sound-ray calculations were made on a CDC-1604 computer at Sandia
Laboratory. Ray paths, travel time, and a multiplicative factor for standard
blast pressure are computed for each 1-degree increment of initial ray eleva-
tion angle. Calculated pressure-distance curves are shown in Fig. 8. Ampli-
tudes have been normalized for 1.2 tons HE at a 15-foot height of burst, peak-
to-peak pressures, and for a 1000-mb ambient sea level pressure condition.
Actual microbarograph data points for the HE calibration shot are shown for com-
parison. Sedan data were scaled to the calibration shot yield and reduced by
the 0.199 average transmission factor. Verification again frequently errs by a
factor of 2. At Argus and Valley Acres in Fig. 8, a and b, significant finite
pressures were recorded in calculated silence zones, although rays were calcu-
lated to land within a few miles of each station. On the average, these ray
calculations slightly over-predict pressures, but this error seems small in com-
parison to the range of random errors encountered.
Atmospheric viscous attenuation, in theory, should reduce the overpres-
sure of ozonosphere signals from the HE calibration shots about 40 percent.
Past experiments gave some indication that this effect was observed, but it
now appears from these data that the R" 1 "2 decay takes this factor into account.
This attenuation mainly absorbs high-frequency waves and would not significantly
affect the Sedan lower frequency waves. If the attenuation were assumed, the
HE data points for Deep Springs, Tom's Place, and Coaldale would be even farther
above the calculated curve or the Sedan data. For the present, viscous atten-
uation is being ignored.
Calculated patterns are rather strongly dependent upon the temperature-
height structure assumed for the ozonosphere. (Rocket measurements were made
only of wind.) There was a small change in the recommended upper atmosphere tem-
perature model between 1959 and 1962. All patterns were calculated and both tem-
perature structures were used in the hope of finding one more useful than the
other. The resulting pressure-distance patterns are quite different in appear-
ance, as shown in Fig. 9, but in reality the differences are small and mostly
22
100
S100 2o * 4
L 10 EARLY, 1040 FPS
ANGUS CHINAIA LAKE
4= * LATE, 960 FPS
A. *EARLY
1VALLEY ACRESj10 -- J1100 1200 1300 1400 100 1600
RANGE(Kft)
L l I Fig. 8B0 700 600 900 i100 I100
RANGE (Kft)
Fig. 8A
S10000
100owo
4 eI *
LONE
0 PINE 10
DEEP BISHOP TON'SSPRINGS PLACE
710 500 60 700RANGE (Kft)
Fig. 8D
* a) ELECTRICAL NOISE MAY HAVE ADDEDTO SIGNAL FROM HE
1.01 I I I * b)NOISE LEVEL REMOVED
500 600 So 0 600 900 1000RANGE (Kft)
Fig. 8C
Pre ssure-amplitude-versus-distance COALDALENEVADA
predictions and observations atvarious direction bearings,normalized to calibration shotyield. to0 Sedan* Calibration Shot
I II500 600 700 600 900 F 000
RANGE (6ft)
23 Fig. 8E
100DIRECTION BEARING 2800
159ATMOSPHERE
- '462 ATMOSPHERE
I'\\ \
- \'
10 I I I500 600 700 800 900
R (Kft)
Fig. 9 Calculated pressure-distance curves from two assumedatmospheric models.
24
reflect changes in ray strike ranges. Also, computed versus observed arrival
times do not indicate an advantage in using either model as shown in Fig. 10.
Focal points and intensities are strongly dependent on detailed temperature
and wind structures, and thus show up as large pattern changes. With the accuracy
of wind observations currently attainable at these levels, however, the assumed
temperature model change is really of little significance; the same holds for
the ragged features of the pressure-distance prediction. Final calculations in
Fig. 8, therefore, were made from the most recent 1962 ARDC Model Atmosphere
temperatures.
In Fig. 8d it is of interest that the Sedan data gave a smoother pressure-
distance curve than did either the HE data or the ray calculation. For long
wavelength signals, it may be true that detailed effects of atmospheric layer-
ing are smoothed. If so, large yield predictions may be made with smaller
errors than are indicated by the bulk of HE data collected to date. Only large
quantities of statistical data could firmly verify this conclusion, but large
quantities would also be required to determine adequately the distribution of
errors when data scatter is as large as has been observed here. It may be of
value on future nuclear cratering tests to increase the number of microbaro-graph observations to determine whether results from large yields are more uni-
form than are those from smaller yields. If so, off-site safety problems posed
by large probable errors and by computed foci may be appreciably reduced.
Verification is graphically shown in Fig. 11, with predicted plotted
against observed pressure amplitudes for the HE calibration shot. Calculated
values are the ranges of pressures predicted to land within 5, 10, and 20 miles
of the station. In every case, a silence zone was predicted to exist within
20 miles of the station. Only the Deep Springs pressure exceeded all predic-
tion; other observed values were predicted to land within 20 miles of the record-
ing station.
Scaling to Large Excavation Yields
Microbarograph measurements on both HE and Sedan shots have been extrapo-
lated to a 50-megaton-yield device at 1.37 ft/(lb) 1 / 3 , or 5040 feet depth of
burst, in Fig. 12. Resulting upper-bound pressure curves for 50 and 10 megatons
are shown. If 4-mb amplitudes are the limit for off-site safety, based on NTS
experience with Las Vegas and St. George, damage could extend 385 miles downwind
(ozonosphere) from the 50-megaton shot or 230 miles from the 10-megaton shot.
25
1000 5
LONE9001 I PIH•E"
Soo 6007080lo -
'59
0
.L35•
VALLEYACRES
1200 1300 14( 15001 - 0
20'59
CHINAAROUS LAK E
I I
500~~ 60 00 0
000O
622
35
APoR NU BISEp PLACE
90011
500 00 700 500
R (Kft)Fig. 10 Calculated mean speeds to wave arrival for two assumed
atmosphe-ric models.26
1000
=DEEP SPRINGS
100TOM'S PLACE -
- ,CHINA LAKEARGUSLONE PINE
COALDALE
aw
coIO0
10
VALLEY ACRES-
EXPLANATION OF SYMBOLISM:
I. RANGE OF PREDICTED PRESSURES WITHIN
MILES FROM STATION2.SILENT ZONE PREDICTED WITHIN
10 .204--mMILES FROM STATION
1.0 I I I I I1.0 10 100 1000
PREDICTED Pk(OWb)
Fig. 11 Verification scatter diagram for HE calibration shot.
27
100 mb
IBM PROBLEM MEXTENSION
(886KT FREE AIR BURST
EQUIVALENT)
0
Ew 1mb 0
m fy
7mb MODERATE WINDOW DAMAGES " .CJ
w 4mb MINIMUM FOR WINDOW BREAKAGE
w
ILwa.
o SEDAN DATA •N \•HE CALIBRATION SHOT DATA ••
,00 , ,b I I I I I I I104 104 I06 10?
RANGE (FEET)
Fig. 12 Pressure-distance data extrapolated to 50-mt cratering shot.
28
If a 7-mb limit were acceptable, allowing for minor damage to smaller towns or
villages which could possibly be provided for by warning and repair arrangements,
then downwind concern would only extend 240 miles from 50-megaton, or 140 miles
from 10-megaton, shots. At crosswind or upwind bearings from these yields, the
range of possible damage from ozonosphere propagations would be considerably
reduced.
CONCLUSIONS AND RECOMMENDATIONS
Conclusions
1. Air blast pressures from Sedan at large distances (100 to 240 miles)
averaged about 20 percent as large as would have been recorded from the same
yield from a free-air burst detonated atthe same time. Specific signal compari-
sons showed that this transmission factor varied from 5 to 35 percent.
2. Rocket wind data and the 1962 ARDC Standard Atmosphere temperatures
allowed ray calculated pressure predictions for ozonosphere propagations to be
made which generally were verified within a factor of 2. Most observed pressure
values were predicted to land within 20 miles of the recording stations.
3. Observed pressure patterns from large shots may be more uniform than
either calculations or scaling from HE calibration shots would indicate. This
may be a result of long wavelengths smoothing out atmospheric detail effects.
4. Results, scaled to 50 megatons at similar WI/3 scaled burst depth,
indicate that minimum window-breaking pressures (4 mb) may propagate to 385 miles
downwind.
Recommendations
1. Future large cratering tests should be documented with similar micro-
barograph measurements to gain further statistical information and to ascertain
repeatability of the average transmission factor.
2. A greater number of recordings should be made on each shot to estab-
lish whether large yield blast patterns are really more uniform than refraction
calculations and HE data would indicate.
29
3. Comparison tests of height-of-burst effects at long range from surface-
burst and 15-foot tower-burst 1.2-ton HE shots should be performed in order that
adequate re-evaluation of Stagecoach data may be carried out.
4. Additional measurements should be made in the second sound ring (200
to 300 miles) to verify the longer range propagation predictions for damaging
waves from 50-megaton cratering blasts.
5. Rocket temperature measurements should be devised to ascertain whether
differences between various standard atmosphere ozonosphere temperatures are real
or pertinent to NTS conditions.
6. Close-in blast measurements above cratering bursts should be made to
establish the source of the relatively large amplitude propagations recorded at
long range.
30
REFERENCES
1. Vortman, L. J., MacDougall, H. R., et al., Project Stagecoach, 20-Ton HECratering Experiments in Desert Alluvium, Final Report, SC-4595(RR),Sandia Corporation, May 1962. (OTS: $4.00)
2. Vortman, L..J., MacDougall, H. R., et al., Project Buckboard, 20-Ton and1/2-Ton HE Cratering Experiments in Basalt Rock, Final Report, SC-4675(RR),Sandia Corporation, August 1962. (OTS: $4.00)
3. Chabai, A. J., Perret, W. R., Reed, J. W., and Vortman, L. J., Mechanismsof Crater Formation, Project Scooter, SC-4602(RR), Sandia Corporation,to be published. (U)
4. Sachs, D. C., and Swift, L. M., Underground Explosion Effects, Project1.7, Operation Teapot, WT-1106, Stanford Research Institute, Menlo Park,
California, March 1958. (U)
5. Reed, J. W., Long-Range Air-Blast Measurements and Interpretations,Project Dannyboy, POR-1809, Sandia Corporation/DOD/AEC, July 25, 1962.
6. Microbarograph Evaluation Report, SC-2990(TR), Division 5231, SandiaCorporation, September 18, 1953. (OTS: $1.50)
7. Smith, L. G., The Measurement of Winds Between 100,000 and 300,000 Feetby Use of Chaff Rockets, Journal of Meteorology, Vol. 17, No. 3, June1960, pp. 296-310.
8. Sissenwine, N., Dubin, M., and Wexler, H., Preliminary Note on the U.S.Standard Atmosphere, 1962, Bulletin of the Amer. Meteor. Soc., Vol. 43,
No. 7, July 1962, pp. 283-287.
9. Broyles, C. D., IBM Problem M. Curves, SCTM 268-56(51), Sandia Corporation,December 1, 1956. (OTS: $1.75)
10. Vortman, L. J., and Shreve, J. D., Jr., The Effect of Height of Explosionon Blast Parameters, SC-3858(TR), Sandia Corporation, June 20, 1956. (U)
11. Church, H. W., Height-of-Burst Effects on Long-Range Propagated BlastPressures, SC-4687(RR), Sandia Corporation, May 1962. (U)
12. Vortman, L. J., Close-in Air Blast from a Nuclear Event in NTS DesertAlluvium, PNE-211F, Sandia Corporation, to be published.
31
TECHNICAL REPORTS SCHEDULED FOR ISSUANCE
BY AGENCIES PARTICIPATING IN PROJECT SEDAN
AEC REPORTS
AGENCY PNE NO. SUBJECT OR TITLE
USPHS Z00F Off-Site Radiation Safety
USWB Z01F Analysis of Weather and Surface RadiationData
SC 202F Long Range Blast Propagation
REECO 203F On-Site Rad-Safe
AEC/USBM 204F Structural Survey of Private Mining Opera-tions
FAA 205F Airspace Closure
SC 21 IF Close-In Air Blast From a Nuclear Event inNTS Desert Alluvium
LRL-N 2 lZP Scientific Photo
LRL 214P Fallout Studies
LRL 215F Structure Response
LRL 216P Crater Measurements
Boeing Z17P Ejecta Studies
LRL 2 18P Radioactive Pellets
USGS 219F Hydrologic Effects, Distance Coefficients
USGS 221P Infiltration Rates Pre and Post Shot
UCLA 224P Influences of a Cratering Device on Close-InPopulations of Lizards
UCLA 225P Fallout CharacteristicsPt. I and II
32
TECHNICAL REPORTS SCHEDULED FOR ISSUANCE
BY AGENCIES PARTICIPATING IN PROJECT SEDAN
AGENCY PNE NO. SUBJECT OR TITLE
BYU 226P Close-In Effects of a Subsurface NuclearDetonation on Small Mammals and SelectedInvertabrates
UCLA ZZ8P Ecological Effects
LRL 231F Rad-Chem Analysis
LRL 232P Yield Measurements
EGG 233P Timing and Firing
WES 234P Stability of Cratered Slopes
LRL Z35F Seismic Velocity Studies
DOD REPORTS
AGENCY PNE NO. SUBJECT OR TITLE
USC-GS 213P "Seismic Effects From a High Yield NuclearCratering Experiment in Desert Alluvium"
NRDL 229P "Some Radiochemical and Physical Measure-ments of Debris from an Underground NuclearExplosion"
NRDL 230P Naval Aerial Photographic Analysis
33
ABBREVIATIONS FOR TECHNICAL AGENCIES
STL Space Technology Laboratories, Inc., Redondo Beach, Calif.
SC Sandia Corporation, Sandia Base, Albuquerque, New Mexico
USC&GS U. S. Coast and Geodetic Survey, San Francisco, California
LRL Lawrence Radiation Laboratory, Livermore, California
LRL-N Lawrence Radiation Laboratory, Mercury, Nevada
Boeing The Boeing Company, Aero-Space Division, Seattle 24, Washington
USGS Geological Survey, Denver, Colorado, Menlo Park, Calif., andVicksburg, Mississippi
WES USA Corps of Engineers, Waterways Experiment Station, Jackson,Mississippi
EGG Edgerton, Germeshausen, and Grier, Inc., Las Vegas, Nevada,Santa Barbara, Calif., and Boston, Massachusetts
BYU Brigham Young University, Provo, Utah
UCLA UCLA School of Medicine, Dept. of Biophysics and Nuclear Medicine,Los Angeles, Calif.
NRDL Naval Radiological Defense Laboratory, Hunters Point, Calif.
USPHS U. S. Public Health Service, Las Vegas, Nevada
USWB U. S. Weather Bureau, Las Vegas, Nevada
USBM U. S. Bureau of Mines, Washington, D. C.
FAA Federal Aviation Agency, Salt Lake City, Utah
REECO Reynolds Electrical and Engineering Co., Las Vegas, Nevada
34
SUPPLEMENTARY DOD DISTRIBUTION FOR PROJECT SEDAN
PNE NO. DIST. CAT. PNE NO. DIST. CAT. PNE NO. DIST. CAT.
200 26, Z8 214 26 226 42
201 2, 26 215 32 228 42
202 12 216 14 229 26, 22
203 28 217 14 230 100
204 32 218 12, 14 231 22
205 2 219 14 232 4
211 12 221 14 233 2
212 92, 100 224 42 234 14
213 12, 14 225 26 235 14
In addition, one copy of reports 201, 202, 203, 211, 214, 215, 216, 217,
218, 221, 225, 229, 230, 232, 234, and 235 to each of the following:
* The Rand Corp. Mitre Corp.1700 Main St., Bedford, MassachusettsSanta Monica, California
Attn: Mr. H. Brode General American Transportation Corp.Mechanics Research Div.
U. of Illinois, 7501 N. Natchez Ave.,Civil Engineering Hall Niles 48, IllinoisUrbana, Illinois
Attn: Dr. N. Newmark Attn: Mr. T. Morrison; Dr. Schiffman
Stanford Research Institute Dr. Whitman
Menlo Park, California Massachusetts Institute of TechnologyCambridge, Massachusetts
Attn: Dr. Vaile
E. H. Plesset Associates1281 Westwood Blvd.,Los Angeles 24, California
Attn: Mr. M. Peter
35